Generally speaking, many retailers are beginning to deploy both customer loyalty cards and coupons to cell phones and mobile devices. This is seen as a way to provide improved customer service and sales as well as gain valuable marketing information. Some retailers are deploying customer id's that allow purchases to be charged against accounts that have pre-paid balances. Almost all of these schemes involve one-dimensional or two-dimensional barcodes that are displayed on mobile screens.
Barcodes that are displayed on mobile screens cannot be read with laser barcode scanners. Mobile screen barcodes can only be read by imaging-based scanners. In addition, these imaging-based scanners must operate differently to read screen-displayed barcodes verses printed barcodes.
For example, the display screens on many cell phones and mobile devices are LED-based which make use of RGB (red/green/blue) emitters. RGB emitters are chosen because they can cover a wide portion of the visible color gamut. Each emitter has a peak wavelength as well as a spectral width associated with it. When all three emitters are viewed against the visible spectrum, a triple peak emission curve is present for a white-lit screen. Other emission sources which may illuminate printed surfaces could be sunlight, incandescent light, white-light LED, warm-white fluorescent bulbs and older style fluorescent bulbs. Imaging-based scanners, in general can't distinguish between the various sources of illumination.
In general, the imaging-based scanners must extend the duration of their exposure when scanning barcodes on mobile device screens. Further, imaging-based scanners need different illumination schemes depending on whether the barcode is printed or on the screen of a mobile device.
If the application requires both printed and screen-based bar codes to be decoded, the imaging-based scanners must either operate in multiple modes, or be able to determine which type of bar code is being presented. Without knowing which type of bar code is being presented, the scanner can appear to be less aggressive with decoding.
Not all applications with mobile device screens involve barcodes, but it may still be advantageous to identify the mobile device screen over a printed surface. Such identification may prompt the scanner or an operator of an image-based scanner to ask certain questions or take certain actions based upon the presentation of a mobile device over a printed surface.
Therefore, a need exists for a system and process to determine whether a presented surface is printed or a mobile device screen and be able to scan the surface with appropriate settings based upon the determination.